A representative for Romney did not respond to a request for comment from Business Insider.

The announcement comes as a surprise to political observers, many of whom predicted Romney would stay out of the 2016 race if another establishment-aligned Republican, former Florida Gov. Jeb Bush, threw his hat in the ring.

Bush, the brother and son of two recent presidents, officially announced he was considering a White House bid in a statement on Dec. 16.

But in December, Business Insider reported that Romney held a meeting that left some attendees convinced he was interested in another run for the White House. Romney, who served as governor of Massachusetts from 2003 until 2007, ran for president in 2008 in addition to his campaign as GOP nominee in 2012.

Over the past year, Romney indicated he would not launch a campaign for president, but his statements left the door to a campaign slightly ajar.

“Someone else has a better chance than I do. And that’s what we believe, and that’s why I’m not running. And you know, circumstances can change,” Romney said in August. “Well, you know, let’s say all the guys that were running all came together and said, ‘Hey, we’ve decided we can’t do it, you must do it.’ That’s the one of the million we’re thinking about.”